Transcription Factors Involved in Brassinosteroid Repressed Gene Expression and Their Regulation by BIN2 Kinase

Plant Signal Behav. 2014;9(1):e27849. doi: 10.4161/psb.27849. Epub 2014 Feb 13.


Brassinosteroids (BRs) play important roles in plant growth, development and responses to environmental cues. BRs signal through plasma membrane-localized receptors to control BES1/BZR1 family transcription factors, which mediate the expression of thousands of genes. BRs activate and repress approximately equal numbers of genes. BES1/BZR1 interact with other transcription factors, histone-modifying enzymes, and transcription elongation factors to activate BR-induced genes. However, the mechanisms by which BES1/BZR1 mediate the BR-repressed gene expression are not well understood. Recent studies revealed that 2 BR-repressed transcription factors, MYBL2 and HAT1, cooperate with BES1 to downregulate BR-repressed genes expression. Moreover, BIN2 kinase, a well-established negative regulator in the BR signaling pathway, phosphorylates MYBL2 and HAT1. While BIN2 phosphorylates and destabilizes BES1/BZR1, BIN2 phosphorylated MYBL2 and HAT1 appear to be stabilized. These results not only extended our understanding of BR-repressed gene expression, but also revealed multiple inputs of BR signaling into BR transcriptional networks.

Keywords: Arabidopsis thaliana; BES1; BIN2; Brassinosteroids; HAT1; MYBL2; phosphorylation; protein stability; signaling.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Brassinosteroids / metabolism*
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant*
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Protein Kinases / metabolism*
  • Transcription Factors / metabolism


  • Arabidopsis Proteins
  • AtmybL2 protein, Arabidopsis
  • BES1 protein, Arabidopsis
  • Brassinosteroids
  • DNA-Binding Proteins
  • HAT1 protein, Arabidopsis
  • Nuclear Proteins
  • Transcription Factors
  • Protein Kinases
  • BIN2 protein, Arabidopsis